Sven Buder
@astrosven.bsky.social
European in Australia. Galactic Archaeologist and sports enthusiast
Most importantly: The data, code, figures, and text are all publicly available for you (and the OJAp reviewers) to reproduce, play with, and follow up on for better and fun science: github.com/svenbuder/ni...
GitHub - svenbuder/nihao_radial_metallicity_gradients: Repository for Buder et al. (2024c): https://arxiv.org/abs/2412.01157
Repository for Buder et al. (2024c): https://arxiv.org/abs/2412.01157 - svenbuder/nihao_radial_metallicity_gradients
github.com
December 4, 2024 at 10:08 PM
Most importantly: The data, code, figures, and text are all publicly available for you (and the OJAp reviewers) to reproduce, play with, and follow up on for better and fun science: github.com/svenbuder/ni...
The gas density & metallicity distribution show a step-like change at spiral arms / gas overdensities. This yet again points at the strong links between gas overdensities & enrichment processes along arms that ultimately drive the local scatter of the metallicity distribution.🌌
December 4, 2024 at 10:08 PM
The gas density & metallicity distribution show a step-like change at spiral arms / gas overdensities. This yet again points at the strong links between gas overdensities & enrichment processes along arms that ultimately drive the local scatter of the metallicity distribution.🌌
The gas reveals sharp changes between leading and trailing edges of spiral arms!
December 4, 2024 at 10:08 PM
The gas reveals sharp changes between leading and trailing edges of spiral arms!
Intrigued by the spiral pattern, we focus on a region similar to what we can currently observe in Milky Way (see Poggio et al. 2021 and others). Our sim. might not have enough stars to fully trace variations around spiral arms in the simulation, but the gas gave us a new hope!
December 4, 2024 at 10:08 PM
Intrigued by the spiral pattern, we focus on a region similar to what we can currently observe in Milky Way (see Poggio et al. 2021 and others). Our sim. might not have enough stars to fully trace variations around spiral arms in the simulation, but the gas gave us a new hope!
The gradient is quite linear in our simulation, but we see some non-linear features! The jury is still out if the function is piecewise linear with a break radius or a smooth (e.g. quadratic) one. Note: A bar (weak in our sim.) could drive strong non-linear behaviour.
December 4, 2024 at 10:08 PM
The gradient is quite linear in our simulation, but we see some non-linear features! The jury is still out if the function is piecewise linear with a break radius or a smooth (e.g. quadratic) one. Note: A bar (weak in our sim.) could drive strong non-linear behaviour.
The challenge to our current observations becomes even clearer when we compare the simulation to data from our Milky Way (left). Is it rather difficult to claim a specific form from the data. The simulation can help us understand why! We can for example test different shapes!
December 4, 2024 at 10:08 PM
The challenge to our current observations becomes even clearer when we compare the simulation to data from our Milky Way (left). Is it rather difficult to claim a specific form from the data. The simulation can help us understand why! We can for example test different shapes!
Tracing these stars is like tracing the blue (and red) poles in a cosmic "Jackson Pollock"! 🎨 Each group aligns with elongated spiral arms. This structure is key to understanding detailed and changing galaxy dynamics—not just in the Milky Way, but across the universe.
December 4, 2024 at 10:08 PM
Tracing these stars is like tracing the blue (and red) poles in a cosmic "Jackson Pollock"! 🎨 Each group aligns with elongated spiral arms. This structure is key to understanding detailed and changing galaxy dynamics—not just in the Milky Way, but across the universe.
We see stars born at the same time with nearly identical [Fe/H], but spread across kiloparsecs in different regions of the galaxy (across 8 sectors in this figure)! This spatial distribution challenges our simplified models of a “linear” radial metallicity gradient.
December 4, 2024 at 10:08 PM
We see stars born at the same time with nearly identical [Fe/H], but spread across kiloparsecs in different regions of the galaxy (across 8 sectors in this figure)! This spatial distribution challenges our simplified models of a “linear” radial metallicity gradient.
In our simulation, we map the galaxy's metallicity in. A linear fit to the radial metallicity gradient works—mostly. But the residuals reveal fascinating spiral structures that demand a closer look. 🌟
December 4, 2024 at 10:08 PM
In our simulation, we map the galaxy's metallicity in. A linear fit to the radial metallicity gradient works—mostly. But the residuals reveal fascinating spiral structures that demand a closer look. 🌟